At what PPM in a UOA is Sodium a concern

[Zaedock]

I recently posted a used oil analysis of my 95% trail use Jeep Wrangler.
http://theoildrop.server101.com/forums/s...ge=0#Post741280

It sees constant slow speed use and very dirty conditions. My used oil analysis showed 13 PPM of Sodium (with 9 being average) and 0 for Potassium. At what level should Sodium be a concern? Do Sodium and Potassium go hand in hand in coolant? I check my fluids before every trail run and I have no perceived loss. I did however, just change my heater core and hoses a week prior to the oil change and sample.
I also have 1.8% fuel, probably due to the low speed trail use. Is there any additive in New England gas that could elevate Sodium? I usually buy gas from Cumberland Farms.
My Jeep is a trail rig and the body doesn't have a strait panel on it, however, my drivetrain is perfect and it bugs me when there could be a potential problem. I researched some past used oil analysis of Jeep 4.0L and 2.5L's and found some to have Sodium ranging from 5-15 PPM and some had low levels of Potassium too. Could this just be normal?

Thanks for your input.

 

[ConfederateTyrant]

Some Sodium comes from dirt and/or oil additives. Since you say you're in dirty conditions, then that's a possibility, plus any road salt could be a problem too. If Sodium was only 13 ppm and you had 0 Potassium, I wouldn't be too scared.

I'm not a used oil analysis expert, but I would be concerned if Sodium and Potassium were both above 20 ppm.